Determination of Intestinal Viral Loads and Distribution of Bovine Viral Diarrhea Virus, Classical Swine Fever Virus, and Peste Des Petits Ruminants Virus: A Pilot Study.

The aim of this pilot study was to determine viral loads and distribution over the total length, at short distances, and in the separate layers of the intestine of virus-infected animals for future inactivation studies. Two calves, two pigs, and two goats were infected with bovine viral diarrhoea virus (BVDV), classical swine fever virus (CSFV), and peste des petits ruminants virus (PPRV), respectively. Homogenously distributed maximum BVDV viral loads were detected in the ileum of both calves, with a mean titer of 6.0 log10 TCID50-eq/g. The viral loads in colon and caecum were not distributed homogenously. In one pig, evenly distributed CSFV mean viral loads of 4.5 and 4.2 log10 TCID50-eq/g were found in the small and large intestines, respectively. Mucosa, submucosa, and muscular layer/serosa showed mean viral loads of 5.3, 3.4, and 4.0 log10 TCID50-eq/g, respectively. Homogenous distribution of PPRV was shown in the ileum of both goats, with a mean viral load of 4.6 log10 TCID50-eq/g. Mean mucosa, submucosa, and muscular layer/serosa viral loads were 3.5, 2.8, and 1.7 log10 TCID50-eq/g, respectively. This pilot study provides essential data for setting up inactivation experiments with intestines derived from experimentally infected animals, in which the level and the homogeneous distribution of intestinal viral loads are required.